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Hypersensitivity pneumonitis

Definition:

Hypersensitivity pneumonitis is inflammation of the lungs due to breathing in a foreign substance, usually certain types of dust, fungus, or molds.

Alternative Names:

Extrinsic allergic alveolitis; Farmer's lung; Mushroom picker's disease; Humidifier or air-conditioner lung; Bird breeder's lung

Causes, incidence, and risk factors:

Hypersensitivity pneumonitis usually occurs in those who work in places where there are high levels of organic dusts, fungus, or molds. For example, farmer's lung is the most common type of hypersensitivity pneumonitis. Repeated or intense exposure to dust from moldy hay, straw, and grain can lead to lung inflammation and acute lung disease . Over time, this acute condition may turn into long-lasting (chronic) lung disease.

The condition may also result from fungus present in humidifiers, heating systems, and air conditioners found in homes and offices. Exposure to certain bird droppings (for example, among bird owners) can also lead to hypersensitivity pneumonitis.

References:

Hoppin JA, Umbach DM, Kullman GJ, et al. Pesticides and other Agricultural Factors Associated with Self-reported Farmer's lung among Farm Residents in the Agricultural Health Study. Occup Environ Med. 2006 Dec 20;[Epub ahead of print].

Lacasse Y, Cormier Y. Hypersensitivity pneumonitis. Orphanet J Rare Dis . 2006 Jul 3;1:25.

Bronchoscopy

Respiratory system

Review Date: 3/16/2007
Reviewed By: David A. Kaufman, M.D., Assistant Professor, Division of Pulmonary, Critical Care & Sleep Medicine, Mount Sinai School of Medicine, New York, NY. Review provided by VeriMed Healthcare Network.

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